This report is a critical evaluation of the Community Analysis Model, a large computer-based mathematical model of growth and change in urban neighborhoods, prepared by a team of M.I.T. scholars headed by David Birch. The computer model has been estimated and solved for six metropolitan areas and has been used to analyze developments, to forecast growth and change, and to plan development in the six places. The Community Analysis Model is the latest and most ambitious . research effort in a history of urban spatial model building that covers nearly two decades. Economists, city planners, geographers and other specialists have contributed to the subject. The Community Analysis Model is the work, primarily, of non-economists. Each large urban model has advantages and disadvantages compared with others. The Community Analysis model has the advantage of freshness of approach to a subject increasingly dominated by economists in recent years. It has the disadvantage that it is not grounded in techniques and findings of economists on the subjects studied.